1967 Impala SS427 L-72?

[bergy]

I agree Mark - never say never, but highly unlikely that documentation exists. I was fortunate to have transfered around GM quite a bit during the late 60s and throughout the 70s (assembly plant, foundry division, Warren R&D). IMO the best chance of finding docs would have been at the assembly plant level. I got to follow a few "executive requests" through the process at the St. Louis assembly plant, but I never recall having kept written documents on them. We did have written AVOs, but didn't file them post build. Government emission certifications were required for drive train combinations - a non-compliant build wasn't something that was advertised. Also, including non-standard components at the assembly line level was an invitation for problems that had the potential of stopping the line - so most of the major "specials" would be done in the repair area or in the garage. All official paperwork (including trim tags) would show a standard build.